1. Field of the Invention
The present invention relates to a photosensitive resin composition, and more specifically relates to a positive photosensitive resin composition suitable for application to the field of microelectronics, and capable of development with an alkali aqueous solution, and a manufacturing method of a semiconductor device using the composition.
2. Description of the Related Art
In the application of microelectronics, polymers that show durability at high temperature are generally well known. The precursors of such polymers, e.g., polyimide and polybenzoxazole (PBO), can be made photo-reactive with proper additives. The precursors are converted to desired polymers by known techniques such as exposure to high temperature. Accordingly, polymer precursors are used for the manufacture of a protective layer, a thermal insulating layer, and a highly heat resisting polymer relief structure.
JP-A-2005-157327 (the term “JP-A” as used herein refers to an “unexamined published Japanese patent application”) discloses a positive photosensitive resin composition containing an alkali-soluble resin, a diazoquinone compound, and γ-butyrolactone and propylene glycol monoalkyl ether as solvents in sum total of both solvents of 70 mass % or more as a composition excellent in sensitivity, prevention of scumming, and film thickness uniformity.
With respect to a photosensitive heat resistive resin composition used as the protective film of a semiconductor, JP-A-2005-148111 discloses in Example 2 that the uniformity of a coated film thickness is improved by the use of a mixed solvent comprising γ-butyrolactone and ethyl lactate.
JP-A-2005-208527 discloses, as a photosensitive coating resin composition having excellent lithographic characteristics and high preservation stability, a composition containing an organic solvent containing 10 mass % or more glycol ethers having specific benzene rings together with specific polyamide and a photosensitizer.
Photosensitive compositions containing these PBO precursors are compositions difficult to obtain sufficient difference in dissolution speed between an unexposed area and an exposed area, so that there remain various problems unsolved such as the uniformity of film thickness after development and curing.